Datasheet

Device
Onboard
MICBIAS.GND
MIC.SUB.P/MIC.MAIN.P
MICBIAS1/2.OUT
C /
C
MM.O
MS.O
R /R
MM.O MS.O
C /C
MM.B MS.B
C /C
MM.M MS.M
MIC.SUB.M/MIC.MAIN.M
R /R
MM.MP MS.MP
C /C
MM.P MS.P
032-033
TPS65950
SWCS032E–OCTOBER 2008–REVISED JANUARY 2011 www.ti.com
Table 6-16. Analog Microphone Bias Module Characteristics (continued)
Parameter Test Conditions Min Typ Max Unit
Output noise P-weighted 20 Hz to 6.6 kHz 1.8 μV
RMS
External capacitor 0 200 pF
Internal resistance 50 60 70 kΩ
NOTE
If the value of the external capacitor is greater than 200 pF, the analog microphone bias
becomes unstable. To stabilize it, a serial resistor must be added.
Table 6-17 lists the characteristics of the analog microphone bias module with a bias resistor.
Table 6-17. Characteristics of Analog Microphone Bias Module With a Bias Resistor
Parameter Test Conditions Min Typ Max Unit
C
B
< 200 pF 0
R
SB
C
B
= 100 pF 300 Ω
C
B
= 1 μF 500
R
B
+ R
SB
2.2 to 2.7 kΩ
6.2.1.2 External Components and Application Schematic
Figure 6-20 and Figure 6-21 show the external components and application schematics for the analog
microphone.
Figure 6-20. Analog Microphone Pseudodifferential
86 Audio/Voice Module Copyright © 2008–2011, Texas Instruments Incorporated
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